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Effect of CYP2C9 *11/*11 genotype on initial and long-term warfarin dose requirement and therapeutic response

Alison Lh Quinn1, Shubha Bhat2, James C Lee3

  • 1National Pharmacy, Kaiser Permanente, Aurora, CO 80011, USA.

Pharmacogenomics
|December 22, 2020
PubMed

The warfarin dose requirement and therapeutic response of a 42-year-old African-American male with genotype CYP2C9 *11/*11, VKORC1 -1639GG and CYP4F2 433Val/Val anticoagulated for ischemic stroke is described herein. Warfarin was dosed according to the institution's personalized medicine program recommendations of a 10 mg mini-load dose, followed by dose decreases to 4-6 mg/day through discharge. Stable international normalized ratio was achieved after eight doses, with good overall long-term maintenance of therapeutic international normalized ratio over several years with warfarin doses of 3.1-4.3 mg/day. This case report sheds further light on the clinical impact of CYP2C9 *11/*11 on warfarin dose requirements, short- and long-term treatment response and practical considerations for warfarin management in suspected carriers of rare variant CYP2C9 alleles.

Keywords:
CYP2C9*11anticoagulationpharmacogeneticsstrokewarfarin

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